Polychrome screen and process of making the same.



U I ED sTAras PATENT carton.

CHARLES L. A. BRASBEUR, 01 NEW YORK, N. Y.

No Drawing.

Specification 01 Letters Patent.

Application filed September 9, 1907. Serial No. 891,964.

Patented Nov. 1, 1910- To all whom 'it may concern:

Be it known that I, CHARLES L. A. BRAS- SEUR, a citizen of the United States, and a resident'of New York city, in the county of New York and State of New York, have invented a certain new and useful Improvement in Polychrome Screens and Processes of Making the Same, of which the following is a specification.

This invention relates to partycolorcd, or polychrome, grained screens intended rimarily for use in color photography an to a process for making the same, and has for its primary object the production of a screen wherein the grains are fiat on both sides, are thin, and touch each other at their edges.

Other objects will appear hereinafter.

It has been suggested (McDonough, United States Patents Numbered 471,186 and t7 1,187 of 1892, Lumiere, French Patent Number 339,223 of 1903) that such screens for making colorhotographs at one exposure be made b t oroughly mixing quantities of three di erently colored grains, and then dustin them promiscuously on a tacky surface. he grains necessarily adhere to the part on which they happen to strike, and remain in the positions they then have, whether that be a corner or an edge down, and, the grains being more or less irregular in sha e, there results a series of irre llar intervals between the colored grains. As 11 Hauron had already indicated in his French Patent Number 83,061 of 1868, it is necessary that the surface of polychrome screens, grained pr lined, be entirely covered by the pattern; that is, that no white light shall come through between the colored grains or other areas. McDonough accomplishes this, according to his said patents,

and makes the colored grains join one another by heatingthe plate until the articles soften and melt, which action, as e indicates, "not only 'oins the grains but also flattens them and makes them more transparent. In the British Patent Number 9,100to Lumiere in 1906, starch rains are suggested and these are crushed rolling up of any interstices that may remain by means of a finely divided black powder. The result in both processes is a polychrome screen, made up 0 an irregular. mosaic of differently colored and sha ed areas, which may be flat on the upper si e but whose under sides are more like ground glass, or are flattened more or less without being parallel to the up 1' sides As such irregularity of areas increases the difliculties one has to overcome when making duplicate positives from an original ne gatlve see my French Patent Number 364,132 of arch 1, 1906), I have endeavored to carry out the requirements of .my said patent b using p0 ychrome screens made u of b ocks of celluloid (as there indicatedl but made by a method now to be described.

Blocks of celluloid or of an anal ous plastic material are made of the desired volume. It cut from sheets, cubes can readily be obtained, with sides running from the one five-hundredth to the one one-thousandth (1/500 to 11000) of an inch. If out from threads, sma 1 cylinders or prisms will be obtained, accordin to the section of the thread. Filaments o artificial silk im regnated with celluloid can also be use but the transparency is not e ual to that of plain celluloid. Once these sma lparticles of transgarent lastic material are obtained, they are yed o theslproper colors and are then rolled between di .s or plates until they assume a spherical shape. The disks may be heated, but I find that the heat enerated by the friction will, in the case 0% such small particles of celluloid, be quite suflicient. to enable them to assume a more or less spherical shape. in a few seconds. Once these imperfect spheres are obtained, it is well to grade them as to size by sifting them one or more times and then to again subject them, in separate lots, to rolling in order to obtain very perfect spheres of equal diameter. Many other materials, natural grains, etc, can thus be converted into spheres, but the treatment of the material to enable it to assume the spherical shape by rolling necessaril varies with the nature of the material .em oyed. It is possible, of course, to make lpo ychrome screens by distributing these particles on a tacky celluloid film or glass.

l with. s sin is la 0t 00 Ans, as is the custom in melting imitatiem Florentine messies and also imitstien marbles te cause the ps-rticles to join me an ether at their edges by submit-tin the Whole to heat and pressure between pellsl'aecl metal. states, the result being s polished. lrnulnicclore messie. dillerent components and which are still somewhst lrregules in slits-see as the tsckiness of the surfs-ice prevents the spheres from rolling lute eenteet was: snethef aml thus assisting symme j of dist lutely necessary te olstsin equality of in the finished se eensq To overcome tne shave-mentioned s culty, l pzeetev pressed as fellewsz sheet of paper or similar msteelel is t eeghly streteleecl on e v 5 fist lJQZUQl er epen trams ll. n

enttr tl wit spheres vs rise cu he clry and new nen-wllaesive mete-F" t as "1 be sen (l a ssive by I melstm (say its to the ll-e s elf the paper stretch as sbeve mentis cl) heat, 01 by liquid by w'ltetevex means will The spray soften time ceetmg sclleeetve metemslo grams terisl be again. ellewed; te harden snarl dry; the surplus layers of spheres can be remeveu therefsem. by meshing tleem elf The re sult is e paper or other svepert eeveteel we spheres, uni-- fesmly :mcl symmetrically dis- 330mm. The paper beet-lug the spheres esn' new be re moved. f tie bested, glass e1 frame, sml be W face clewn en te a thin t l I L refembly flowed en a, pelfslmezl metsl piste-z The film be slmest alt y befere the transit era is meals, But, in the. case of seedy-meals films, it isbest s' my it over with e selvent es pert-ital sel'v 0f celluloid s0 es teteeilitete sdhesien between the spheres the film. in the at imitstiem Flesentise -messice the whole is new submitted te hest pres me Wlllfih causes the spheres ts flatten nut, e61 ere t0- getltes end. tc the laetteetlm In elder ts sveiilsny tendency for the spheres ta mm inter eselz etuthet the s hesemeveretl pepew em hsve spmyecl ever 3i; e tltln'selutiezl et gelstin with seiql 01." otltet isclstlmg materiel,v case "being taken te pass as st) ens? spacing which is slxse met tsphetes) will new become eflteremt t0 the paper ssppert and; ti the ssneswe ma.

sosbingrcller over all to clean oil tlist part at the spheres whleh 1s t0 come mte contact Witltthe film crest-21in some at the s heres 7 & 5

beeu peessed en tl'ne celluloid film, the Whole is allowed to seal and the paper is then re Weill by means sf suitable selvent the s he'sive material an it Any interstices seme ning in the screen can new be filled up by rabbi of eellulmclg A thin selutien of cellul is then sprayed span the smfece which been in cemtsct the paper, and the .I is lSllGfl between lmt metal plates his ll prefer ts use a pewcle? at the three celess es the colors already on plate or filmv I (la) not limit myself t0 sseh powder;

1-11 any 1' tween the t be elmlae s tu tl e gla't tram the reverse side se exgeese only the gelstm belunfii such action of White light and Wlll become msolubtltzed. be remevedl Wllll lmt att color, thus blame out The film, in sueh'plsces, ever with celluloid cl, .Clhe film will 2' w f we mus opem-tiens neces upon it s sensitive phetogsspltic Wllielr. is t0 be termed the megw live or the posit lit is elwieus s the spheres can be plied direc y ts t as celluloid film if thi we perfectly (as on s metal plate) e1 be semleree zmlltesive and this m turn b lewecl te became almost clrv lse'feresppls the sphetfes but it is hard to malts emmess pelyelmome films by this metltmlnf The llfiniffil metlwtl otters many sch/statsgeew It ellews (me to supply monochrome lbsncls the di" celerecl spheres along the eeges'er ether suitable places; the uses of tlese bench has been indicated in prim sp plicstlems of mine. It also allows One make endless elyehmme films for k'lnemstegraphic purposes, 01 01" sell film csmezi by tmnsfeming gr'einecl paper to the mailless end after removal of the paper White filling tip the gaps, if any, by-applying:

eiseugh celluleicl may be spfeyed oven the surface ts gwe the fimshecl film sufielent ill approptietelycelored pevqcler consistency and to make sure that the mosaic bichromated gelatin is first spread on the glass, and when this is dry, the back .of the plate is exposed to the light for a few seconds so as to insolubilize that part of the. gelatin which is in immediate contact with the glass. The plate is now washed in cold water to remove all soluble chromates. After drying, a thin solution of celluloid containing glacial acetic acid or other common solvent of gelatin and celluloid, is

' pouredlover the plate, the acetic acid will slightly dissolve the soluble gelatin and the result will be a layer of celluloid firmly welded to the underlying gelatin which is itself firmly adherent to the glass. The remaining soluble gelatin between the celluloid and the glass must be rendered insoluble by being soaked in a hardening solution. After washing and drying, it will be found practically impossible to remove the film from the late. The plate can now be treated as if it were a celluloid film, and have the spheres placed upon it in the same way.

, It is clear that this method of making polychrome screens can be applied to the production of screens for other photographic purposes. Thus, in my said patent of March 1, 1906, I describe a mosaic made up of three pure colors, and in which the sum of the surfaces of the different colors are proportioned to the time required to impress the sensitive plate in the manner described in that patent. A screen made up of minute particles and forming a perfectly homogeneous layer, such as resu ts when the operations described herein are properly carried out, can be used not onl in contact-printing as described in my said patent of March 1, 1906, but can also be used while copying with the camera, as these new screens can be used, cemented between glasses if need be, either before or behind the lens or at the diaphragm plane of the lens or closely adjacent thereto and fulfil the same purpose as the radial screen described in my said patent.

Black and white half-tone screens can also be made by means of these s heres, In such opaque spheres, the one requisite of the opaque spheres being that they be opaque to the rays which affect the silver salts used in copyin The black and white screens can be ma e of any fineness, as one hundred and fifty, one hundred and seventy five, or two hundred or more to the inch, by taking spheres of an ap ropriate diameter for making the same. he black and white screen had better be sealed between two glasses, but film screens can also be made for contactprinting, the spheres in such case being pressed in contact with a film of such thick ness as will answer the theoretical requirements of screens when used in this manner. Half-tone screens, when made -in alternate squares, are ver luminous as compared with ordinary cross ined half-tone screens. The mechamcal or symmetrical effect of the half-tone screen may be broken up by using grains or spheres of unequal diameters; such a screen also avoids the moire-effect arising from the use of lined screens in color-printiymmetrical or pattern effects in color screens for color photography may also be avoided by havin the differently colored spheres of unequa diameters, but, in such case, the quantities of each color must be so chosen as to secure equal areas (in the aggregate) of the three colors.

The spheres or grains of any sha instead of being mixed together can E2 apl sup ort by plied to the temporary or fina istributing machines fitted with fee ing devices which Will feed spheres or ains of only one color at a time and moving back and forth atsuch a speed that the spheres or grains fed by one feedin device will form a continuous row, the different colors being fed in different rows, thus securing more symmetrical color-distribution than in the case of first mixing the different colors and then dusting them on a tacky surface. \Vhile the spheres are still upon the paper support and before the adhesive is rendered tacky, the spheres ma be caused to pack together more closely y shaking slightly or by tapping the late or frame, thus leading to the distribution of the spheres six about one, and to the formation of hexagons on the finished screen.

The supporting film may be made of celluloid, viscose, or other suitable material.

\Vhat I claim-as new and desire to secure by Letters Patent of the United States is- 1. The method, substantially as hereinbefore set forth, of forming grained screens for use in photographic processes, consisting in forming as spheres grains of different light-selective absorption properties, distributing said grains in a layer on a support, flattening them out andbinding them toether.

2. The method, substantially as'hereinbe- 3, A screen a for photographic processes consisting of grains of different light-selective absor tion properties integral With a colorless lm of the same material as the grains.

4. The method, substantially as hereinbefore set forth, of forming grained screens for use in photographic processes, consisting in placing a quantity of grains of difierent light-selective absorption properties upon an adhesive substance backed by paper and in a dry or non-tacky state and causing them to pack close together, rendering said adhesive substance tacky and then drying it again, removing surplus grains, then transferring the layer to a colorless film, flattening the grains, and binding them together and to said film.

5. A screen for use in photographic processes consisting of thin fiat grains of difierent colors forming a layer coated on one side at least with a thin layer of colorless material and integrally connectedwith said grains, the whole forming an endless film which can be rolled up and unrolled in film canieras and hinernatographic Work.

. 6. The method, substantially as hereinbe: fore set forth, of forming grained screens for use in photographic processes, consisting in cutting minute blocks from a colorless transparent material, dyeing the same to give them different light-selective absorption properties, distributing said blocks in a layer on a support, flattening them out,

and binding them together.

7. The method, substantially as hereinbe fore set forth, of forming grained screens for use in photographic processes, consisting in cutting minute blocks from a colorless transparent material, grading said blocks to size, dyeing the same to give thorn difi'erent lightselective absorption properties, distributing said blocks in a layer on a support, flattening them out, and binding them'together.

8. The method, substantially as hereinbefore set forth, of forming grained screens for usein photographic processes, consisting in placing a quantity'of grains of difierent light selective absorption properties upon an adhesive substance in a dry or non- -sticlry condition and causing them to paclt'closlely,

together, rendering said; substance adhesive,

erases then drying it again and removing the surplus grains.

9; The method, substantially as hereinbefore set forth, of forming grained screens for use in photographic processes, consisting in placing a quantity of grains of diderent light-selective absorption properties upon an adhesive substance, causing them to pack closelytogethen in a single layer, and trans ferring' the said layer to a film and binding them together and to said film.-

10. The method, substantially'as hereinbeforc set forth, of forming grained screens for use in photographic processes, consisting in placing a quantity of grains of dif-- ferent light-selective absorption properties u on a transfer surface coated with a solublea esive substance, causing them to pack closely together in a single layer, and transferring the said layer to the surface of the screen, by placing the transfer surface with the grains adhering thereto face down on the screen, dissolving the adhesive substance and removing'the transfer surface, and binding the grains together and to said film.

11. The method, substantially as hereinbefore set forth, of forming grained screens for use in photographic processes, consisting in placing a quantity of grains of different li ht-selective absorption properties upon an a hesive surface, applying an isolating material to said grains to keep them separate, and applying heat and pressure to the whole, to cause said grains to flatten, adhere together and to the surface on which they rest.

12. The method, substantially as herein- I been insolubilized by the action of light,

and dyeing that which remains.

13. The method, substantially as hereinbefore set forth, of forming grained screens for use in photographic processes, consisting in cutting 1 minute blocks from a colorless transparent material, forming the same intospheres, dyein the same to'give them different light-so ective absorption properties,

distributing said spheres in a layer on a support, flattening them out, and binding them together.' l t. The method, substantially as hereinbefore set forth, of forming grained screens B I0l tlS8 1n pnotographic processes, consisting ioo in cutting minute blocks from a colorless Signed at New York city in the county transparent material, forming the same into of New York and State of New York this spheres, dyeing the same to give them difseventh (1a of September, A. D. 1907.

ferent light-selective absorption properties, C ARLES L. A. BRASSEUR. 5 grading them according to size, distributing Witnesses:

the spheres ina layer on a support, flatten- T. F. KEHOE,

ing them out, and binding them together. 7 R. V. BARKLEY. 

